Study links genes to social behaviors, including autism

October 18, 2018, Princeton University
Sweat bees nest in the ground in either small colonies consisting of a queen and workers, or alone. Researchers compared the genes of social versus nonsocial bees to find correlations between genes and behavior. Image courtesy of Princeton University researchers. Credit: Princeton University researchers.

Those pesky bees that come buzzing around on a muggy summer day are helping researchers reveal the genes responsible for social behaviors. A new study published this week found that the social lives of sweat bees—named for their attraction to perspiration—are linked to patterns of activity in specific genes, including ones linked to autism.

"Bees have complex social behaviors, and with this species of bee, we can directly compare individuals that live in social groups to those that don't live in social groups," said Sarah Kocher, an assistant professor of ecology and evolutionary biology and the Lewis-Sigler Institute for Integrative Genomics at Princeton University, who led the research. "We can ask: 'What are the fundamental differences between a social and nonsocial animal?'"

The researchers found that one of these differences involves the gene syntaxin 1a, which governs the release of chemical messengers in the brain. In all, the study found nearly 200 gene variations that were linked to social behavior, with 21 clustered in or nearby six genes implicated in human autism. The study was published in the journal Nature Communications.

Sweat are ideal for studying the genes underlying social behavior, Kocher said, because some are naturally social while others are solitary, even though both types belong to the Halictidae family. Both types nest in the ground, but the live in a hierarchal society consisting of a queen and workers, like their honey bee relatives, while nonsocial live alone.

Fields of yellow flowers provide habitat for sweat bees. Credit: Princeton University researchers.

Until Kocher began studying bees, not many scientists had looked at the mechanisms underlying their behavior. One of the few scientists to have studied the bees was Cecile Plateaux-Quenu, an entomologist who in the 1960s documented sweat bee populations—and their social habits—in sites around France.

In 2010, Kocher located the retired scientist and eventually traveled to France to meet her. Plateaux-Quenu helped the younger scientist learn to identify the bees, find their nests, and net the insects as they traveled among the dandelions, asters and daisies.

Kocher, who was then a postdoctoral researcher at Harvard University, brought the bees back to the laboratory to analyze their genes. She sequenced the genomes of hundreds of bees of the species Lasioglossum albipes, known from locations that Plateaux-Quenu had classified decades earlier as home to either social or solitary bees. Next, the researchers looked through the genetic data to detect correlations between patterns of gene activity and social behavior.

The findings suggest that variations in several genes play a role in causing or contributing to the social behavior of these bees. Many of the variations detected were found in sections of the genetic code that are not genes themselves but rather regulate other genes by enhancing their activity.

Researchers at Princeton University have found genes linked to social behavior in bees that are also linked to autism in humans. Credit: Catherine Zandonella, Princeton University

Social behavior is complex and is determined by multiple genes rather than a single gene. Genes are important for brain development—they orchestrate connections between neurons and pruning of those connections during development and childhood.

Another study conducted last year on honey bees also found a link between bee genes and autism genes. One of the differences between that study and this new one, Kocher said, is that honey bees are by nature social, whereas sweat bees can be either social or nonsocial.

"It came as a surprise that we came across the same results independently," Kocher said. "It suggests the existence of a core set of that play an important role in shaping across different species," she said.

Explore further: Evolution: Genetic relatedness doesn't matter much in forming society

More information: Sarah D. Kocher et al, The genetic basis of a social polymorphism in halictid bees, Nature Communications (2018). DOI: 10.1038/s41467-018-06824-8

Related Stories

Halictid bees' social behavior studied

March 13, 2006

Cornell University scientists say the social behavior of many species of sweat bees evolved simultaneously during a period of global warming.

Similarities found in bee and mammal social organization

June 30, 2016

New research shows similarities in the social organisation of bees and mammals, and provides insight into the genetics of social behavior for other animals. These findings, published in PLOS Computational Biology, use sociogenomics ...

Recommended for you

Venom shape untangles scorpion family tree

November 14, 2018

As a child growing up in Mexico, Carlos Santibanez-Lopez feared the scorpions that would often decorate the walls and ceilings of his home in search of a warm place with plenty of food.

Gene-edited food is coming, but will shoppers buy?

November 14, 2018

The next generation of biotech food is headed for the grocery aisles, and first up may be salad dressings or granola bars made with soybean oil genetically tweaked to be good for your heart.

Visualizing 'unfurling' microtubule growth

November 13, 2018

Living cells depend absolutely on tubulin, a protein that forms hollow tube-like polymers, called microtubules, that form scaffolding for moving materials inside the cell. Tubulin-based microtubule scaffolding allows cells ...

DNA structure impacts rate and accuracy of DNA synthesis

November 13, 2018

The speed and error rate of DNA synthesis is influenced by the three-dimensional structure of the DNA. Using "third-generation" genome-wide DNA sequencing data, a team of researchers from Penn State and the Czech Academy ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.